Abstract As one of the most vital organs in the human body, the heart functions as a potent biological pump that actively delivers/recycles the blood towards/from all other organs through the vascular system. As a result, the capability to regenerate an injured or diseased heart has always been a focus in tissue engineering and regenerative medicine. Over the past few decades, the field of cardiac tissue engineering has seen tremendous progress in fabricating functional cardiac tissues that largely recapitulate the biology of the heart, but challenges remain, including the alignment of cardiomyocytes and their organization into bundles as well as the introduction of microvascular networks into engineered thick cardiac tissues. Beating of the cardiomyocytes poses another major obstacle. While cardiomyocytes beat synchronously in the heart, such capacity can be easily lost during in vitro manipulation. Methods based on electric stimulation and inclusion of electroconductive materials that improve the spontaneous and synchronous beating of engineered heart tissues have been proposed, which are critical to the successful integration of these engineered cardiac tissues with host to achieve functional regeneration. However, the most commonly used approaches for applying the electrical stimulation such as paired electrodes or multi-electrode arrays are limited in their ability to integrate with engineered cardiac tissues for applications in regeneration due to the stiff, non-compliant nature of these electrodes. Recent advances in the field of soft flexible and stretchable electronics have provided effective means to interface compliant electronic devices with human organs including the heart, which have rarely been adapted to combine with engineered tissues for improved functions. The overall goal of this proposed project is to develop a hybrid of soft stretchable network fashioned electronics and bioprinted cardiac tissue for conformal, in situ electrical stimulation and recording of cardiac signals, where the stretchable network formatted electronics will be designed to be biodegradable to match the rate of regeneration and the cardiac tissue aligned with embedded vasculature will be generated using a novel microfluidic bioprinting strategy.